Cabrini Marina, Calignano Flaviana, Fino Paolo, Lorenzi Sergio, Lorusso Massimo, Manfredi Diego, Testa Cristian, Pastore Tommaso
Department of Engineering and Applied Sciences, University of Bergamo, 24044 Dalmine, Italy.
INSTM Unità di Ricerca Bergamo, Dalmine, 24044, Italy.
Materials (Basel). 2018 Jun 21;11(7):1051. doi: 10.3390/ma11071051.
This experimental work is aimed at studying the effect of microstructural modifications induced by post-processing heat treatments on the corrosion behavior of silicon-aluminum alloys produced by means of laser powder bed fusion (LPBF). The manufacturing technique leads to microstructures characterized by the presence of melt pools, which are quite different compared to casting alloys. In this study, the behavior of an AlSi10Mg alloy was evaluated by means of intergranular corrosion tests according to ISO 11846 standard on heat-treated samples ranging from 200 to 500 °C as well as on untreated samples. We found that temperatures above 200 °C reduced microhardness of the alloy, and different corrosion morphologies occurred due to the modification of both size and distribution of silicon precipitates. Selective penetrating attacks occurred at melt pool borders. The intergranular corrosion phenomena were less intense for as-produced specimens without heat treatments compared to the heat-treated specimens at 200 and 300 °C. General corrosion morphologies were noticed for specimens heat treated at temperatures exceeding 400 °C.
这项实验工作旨在研究后处理热处理引起的微观结构变化对通过激光粉末床熔融(LPBF)生产的硅铝合金腐蚀行为的影响。该制造技术导致的微观结构以熔池的存在为特征,这与铸造合金有很大不同。在本研究中,根据ISO 11846标准,通过晶间腐蚀试验评估了AlSi10Mg合金在200至500℃热处理样品以及未处理样品上的行为。我们发现,高于200℃的温度会降低合金的显微硬度,并且由于硅析出物的尺寸和分布的改变,会出现不同的腐蚀形态。在熔池边界发生选择性穿透侵蚀。与在200和300℃热处理的试样相比,未经热处理的试样的晶间腐蚀现象不那么强烈。对于在超过400℃温度下热处理的试样,观察到全面腐蚀形态。